The Impact Of Climate Change On Water Resources: Global And Nigerian Analysis

Abstract

This paper investigates the impact of climate change on global and regional water resources. Primary climatic data (Rainfall and Temperature) for Nigeria were collected from the Nigeria Meteorological Station, Lagos between 1960 and 2002. Changes in Lake Chad waters were collected from the National Centre for Remote Sensing (NCRS), Jos. World temperature and water resources data were collected from different sources. The data were analysed using percentages and time series among others. The result shows that the atmospheric concentration of most greenhouse gases (GHGs) is increasing and this has resulted to changing global climate with increasing temperature. The rise in global average temperatures since 1860 now exceeds 0.6 O C. The effect of the GHGs concentration on global warming as at 2100 is estimated by three scenarios to be 1.5 O C (Low), 2.5 O C (Middle) and 4.5 O C (High). In Nigeria, while rainfall has decreased by 92 mm, temperature increased by 0.8 O C since 1960. This has led to increasing evapotranspiration and water stress resulting in the drying up of rivers and lakes. For example, Lake Chad has reduced in size from 22902 km 2 in 1963 to 16884 km 2 in 1972 and 304 km 2 in 2000. While climate change will make some countries to experience increase in water resources, majority will face serious water stress. Based on projection, by the 2080s, most countries in the Middle East, around Mediterranean, part of Europe, North and South Africa will face acute water stress while Southern and Eastern Asia, U.S.A. and Alaska. will experience reduction in water stress. By the 2020, 2050, 2080s the total population that will face increasing water stress due to climate change will be 2.3, 3.2 and 3.7 billion respectively. Some recommendations were made to reverse this ugly situation.